A harvesting machine, such as a combine or self-propelled forage harvester, is typically used to harvest large quantities of agricultural material, such as grain or silage, in a field. Typically, harvesting machines utilize a spout (e.g., an unloading auger) to transfer agricultural material to a storage portion (e.g., a grain cart or wagon), of a receiving vehicle (e.g., a tractor). The material transfer/unloading process may occur when the harvesting machine and the receiving vehicle are stationary. Alternatively, the material transfer/unloading process may occur on-the-go, while the harvesting machine and the receiving vehicle are moving and the harvesting machine is simultaneously harvesting agricultural material.
When unloading on-the-go, the operators of the harvesting machine and the receiving vehicle must work together to maintain cooperative alignment therebetween to prevent spillage of agricultural material outside of the storage portion and to achieve a desired distribution of material within the storage portion. Desired distributions of material may optimize the material fill level by avoiding unused space within the storage portion. By achieving a desired distribution and avoiding spillage, the operational efficiency of the transportation of agricultural material from a field to a grain bin may be optimized. Controlling the spout position while maintaining cooperative alignment is a challenging process because an operator of the harvesting machine must monitor various controls relating to harvesting the crop in front of the harvesting machine, while simultaneously monitoring and controlling the material transfer process to the side of the harvesting machine. Further difficulties arise because the operator may not have a clear line of sight into the storage portion.